Function doesn't return an object

Hi there.

I've built a class that contains an array of characters and implements several methods to manage the array.

I want to redefine operator + so an instruction like b = a + 'x' adds the character 'x' to the array contained in a and puts the result in the array contained in b.

This is what I try:

Code:

// This function is supposed to manage this kind of instructions:
//   b= a+ 'x' , where a and b are instances of SetOfChar.
//   Of course, a is referred as 'this' inside the function.

SetOfChar SetOfChar::operator+(char c){

      // 1) Create a new object with same data than this (a)
	SetOfChar res(*this);    

      // 2) Add the character
	res.addChar(c);

      // 3) RETURN THE RESULT AS AN OBJECT (doesn't work!)
	return res;
}

I've also tried to return a reference to the local object instead of the object itself, but it won't work.

Both the constructor and the addChar method work properly.

How am I supposed to create an object inside a function and then return it as a result?

Thanks in advance.

If your copy constructor works then the problem lies with the assignment operator. In general if you have to write a copy constructor, assignment operator or destructor you need all three. Normally binary operators that return temporaries are built as free function syntatic sugar out of '+='

Code:

class foo {
    public:
    foo & operator += (char c) {... return *this;}
};

inline foo operator + (const foo &f, char c) { return foo(f)+=c; }

I found out that my problem was that I hadn't declared operator = , so I couldn't make the expression b = a + 'x' work properly.

After all, the function DID return the object correctly.

Anyway, I also made the changes you suggested, as it's a much more elegant solution than the one I used before.

Thank you very much for your answer.